A high-throughput sequencing approach was used to differentiate the nematode communities in the humus and soil surface layer (0-10 cm) in 20 hm2 plot located in the cold temperate coniferous and broadleaved mixed forest of Yulong Snow Mountain Nature Reserve, Lijiang, Yunnan. A total of 5744582 sequences were obtained, which were further annotated to 44 nematode families. In the humus layer, 37 families were recorded, with Tylenchidae (18.1%) being the most dominant family. For trophic groups, bacterivorous, fungivorous and herbivorous were predominant. The soil surface layer had 41 families, with Mononchidae (45.4%) being the most dominant family. The relative abundance of predatory nematode was highest in the soil surface layer. There was no significant difference in the α diversity indices (Shannon, Simpson and Chao1 index) of nematode communities at the OTU level between two habitats. At the family level, however, α diversity of nematode community in the humus layer was significantly lower than in soil surface layer. β diversity of the nematode community was significantly different in the two habitats, with lower Cody index but high Sorensen non-similarity index in the humus habitat. Results of non-metric multidimensional scaling (NMDS) analysis showed that the internal structure difference of nematode community in the soil surface layer was higher than that in the humus layer.
采用高通量测序的方法,对位于云南省丽江玉龙雪山自然保护区20 hm2寒温性针阔混交林中腐殖质层和土壤表层(0~10 cm)线虫群落结构的差异进行了研究。共获取测序序列5744582条,注释后获得44科线虫。腐殖质层线虫有37科,其中垫刃科(18.1%)为优势类群,营养类群以食细菌、食真菌和植食性线虫为主;土壤表层线虫有41科,单齿科(45.4%)为优势类群,捕食性线虫具有最高的相对多度。虽然在操作分类单元(OTU)水平上两个生境线虫群落的α多样性(Shannon、Simpson和Chao1指数)无显著性差异,但在科水平上,腐殖质层线虫群落的α多样性指数显著低于土壤表层;两个生境的β多样性有较大差异,其中腐殖质层Cody指数低于土壤表层,而Sorensen非相似性指数相反。非度量多维标度(NMDS)分析表明,土壤表层线虫群落内部结构差异大于腐殖质层。.
Keywords: community structure; high-throughput sequencing; humus layer; soil nematode; soil surface layer.